Here's the latest, after installing the Spec 3+ w/ SLP flywheel i drove the car a bit Saturday and i bleed it a couple more times and no change with the disengagement. It still engages right off the floor and it does drag a little bit doing the rev test so i parked it cuz i don't want to wear out the new clutch. i ordered the Tick adjustable master cylinder and they said it will fix my problem.

One thing i thought of is the pedal is damn hard to push in once the "dead space" is gone aka when its actually moving the pressure plate. i'm assuming this is normal for being such a stiff clutch but i'm worried that with the Tick MC that it will add 15% pedal pressure i won't be able to work the clutch without steroids.....

And i didn't mention this before but the car has a vibration from 2-3000rpm now and its not tranny or rearend related. but does seem to be magnified when moving. You can sit still and rev it and it vibrates like crazy but smooths out after 3k...... what the hell is that? i'm assuming its the clutch or flywheel out of balance? What now? Everything is aligned right using the dowels and torqued right...... i'm just hoping that everything will be fixed once i get the new master cylinder.
Oh, i did install the DTE strut brace while it was all apart but i know its installed right and the right amount of turns on the rods etc.

 

Seems these spec clutchs are sensitive. If you have a vibration problem after a cluch install, you have a balance issue.

 

You state that the clutch is hard now. After the Tick, you will see an increase in pedal pressure.

 

There is another thread on here with a Spec problem.

ALWAYS have the flywheel balanced or even the clutch and flywheel together, I had mine balanced for $20 and it was about 18 grams off if I remember correctly (enough for it to cause a off balance issue). You may need to shim due to the low pedal engagement. I would not go with the Tick cause as stated above its going to make the pedal harder and not the 15% as you heard, many report 40-50% heavier pedal. I would look into doing this mod to your stock master to get a tad more throw before taking it all apart to shim it http://www.ls1tech.com/forums/manual...r-writeup.html but since you have a balance issue you might as well shim it anyway. The stock master mod does not make it any hearder to press the clutch at least it did not for me.

 

I just installed a Spec Stage2 on my 98 coupe,and,maybe I just got lucky,but it works great,and no vibration issues-

When you first took the clutch/flywheel assy out of the box,did you mark which dowel pin went in which hole before you separated them?

The reason I'm asking(and this may or may not be related to the balance issue),is I noticed that on the pressure plate,there is 1 small weight riveted on,that,on my assembly,anyway,was located pretty much in the same location on the edge of the pp,as the index hole in the flywheel,possibly to make up for an imbalance caused by the index hole itself?

If the pp didn't go back on the flywheel the same way it was shipped,then it seems like the "heavy" side of the pp,would be opposite he "light" side of the flywheel.

I may be splitting hairs here,since I'm not really sure how much weight it takes to cause a noticeable vibration in a rotating assembly with the mass of a flywheel & pressure plate,and possibly the weight was lined up with the index hole just by coincedence- I'm just mentioning what I noticed on the clutch assy I installed.


Good luck with the issues you're having-Really hope you can get them ironed out without having to tear into your Vette again-

 

Did you follow the procedure in the service manual that calls for locating and removing the balance weights off the old flywheel and re-installing them on the new fly-wheel at the same location?
These engines are externally balanced, there is a similar procedure for the harmonic balancer (crank pulley). I would not operate it with that imbalance for long, it will have to come apart again.

 

How in the world is taking the stock flywheel weights off and putting them on the new flywheel gonna help anything? Thats like a blind man balancing a tire. It aint gonna work cause they are 2 different flywheels.

 

Because you're not trying to zero out imbalances in the flywheel/PP itself, but assist in balancing the entire rotating assembly. If you get the flywheel & PP balanced (or at least verified), that's good, but you still need to add those trim weights back in.

HTH, and have a good one,
Mike

 

So if I got a PP and flywheel balanced and added those factory trim weights back then its gonna be out again. Whats the use in even doing that? Makes no sense at all. I have never put those factory weights back on a aftermarket flywheel and never ever had a problem with any drivelines vibrating...
Only way it makes sense if the aftermarket clutch assy/flywheel weighed EXACTLY the same as the stock setup which we know it isnt.

ie: I buy a new tire and balance it on the rim..then I put the old weights back on in same position they were with old tire...ummm okie dokie...
To each his own I guess...

 

Mixing apples and oranges. Question: How do you take care of the imbalances within the rotating assembly (crank and connecting rods)? Either internally by removing weight from the crank flyweights or externally via the harmonic damper and/or flywheel.

As mentioned above, the LS-1 is externally balanced. The harmonic damper isn't used for balancing (one clue is that it isn't keyed), so the alternative is the flywheel. The reason you balance the flywheel/PP is to keep them from making an unknown "contribution" to balancing the rotating assembly.

The reason you haven't had any problems before was either 1.) the engine's were balanced internally or 2.) the amount of weight the engine needed was minimal.

BTW, to the OP, another source of vibration is flywheel wobble. This can be caused by an out of plane flywheels surface (happened to me when I had a flywheel resurfaced by a shop with a great reputation but lousy execution) or by, believe it or not, improper torqueing of the flywheel bolts. This happened to a friend's '00 LS1 from the factory!

HTH, and have a good one,
Mike

 

This is the first time I'm hearing about taking weights off the factory flywheel, and placing them on your aftermarket FW. Does this apply to LS6s as well. How are they attached/re-attached?

 

If you have a problem with this procedure take up with the GM power train engineers or service technicians that wrote this portion of the service manual. I followed these directions and do not have imbalance problems at any RPM.

Incorrect, the flywheel only goes on one way, the location of the weights relative to the crank position is important. The procedure for the harmonic balancer replacement specifically tells you to mark the balancer and crankshaft snout noting the relative position of the balancer on the crank; remove the weights and install them in the same locations on the new balancer, and then re-install the new balancer in the same relative position as the old so the weights end up at the same locations.
Don't take my word for it, read the SERVICE MANUAL!

 

That's what I've been saying, so we're in agreement.

I checked, and stand corrected. Curious that the damper isn't keyed, and I've seen several dampers that had slipped on the crank snout (one didn't have the crank pulley bolt tightened sufficiently and spun off completely). I guess it just isn't as big a player with the reduced damper diameter.

Thanks for the clarification, and have a good one,
Mike

 

Your are correct, but this only applies to a balancer used on a manual trans.

 

I'm aware of this, no offense but we are talking about an imbalance problem on a manual transmission application aren't we?

 

Indeed....just covering the bases since everyone does not have the service manual....

 

There in lies the lies the problem, I bought my service manual used for under $100.00, the return on investment is probably a hundred fold by now.

 

I hear ya, I own one for all my vehicles. Hell, I've even got one for my snowblower....

 

so back to the basics though... its a brand new SLP flywheel and new Spec clutch/PP and it never mentions balancing anywhere so i'm confused why this would be sold if it was unbalanced or need balanced etc......
Installation was as simple as i lined up the dowel hole from crank to extra flywheel hole and used the dowels to locate the PP the only way it can go on. Yes the Spec PP had a brass weight attached to one side of the PP & the gap was .050" so i couldn't use the shim it came with was .110" thick. i used the GM service manual to the T and everything is perfect.

The strange part is why would the vibration go away after 3k rpms? i'd think the vibs would get worse or at least change frequency?
What are the chances that the adjustable master cylinder will fix all my problems since i know i have a disengagement issue?

I guess my problem is i'm basing all this stuff off of what i've read, heard, seen, & reviews. I used the Tick & Ram gap procedure to measure the gap and didn't use the shim and as soon as its back together i read i should use the shim even though it says in the Spec instructions that generally C5's don't need the shim, I buy a Spec cuz everyone says its what i need for drag racing and my soon to power, but now i shouldn't of bought a Spec, I got a lightweight Yella Terra flywheel cuz its what i need but wait don't use it since i drag race not road race like they thought i said so i had to take it back apart so put in the correct weight and best money can buy SLP standard weight flywheel, now the piece of crap vibrates and its because of the flywheel....and the package doesn't disengage....so to fix the disengagement problem buy the Tick adjustable MC so i do and now i read i shouldn't of because it makes the pedal even worse............ sorry for whining but i don't know what to do next. This project was supposed to be relatively simple to do before winter i can only imagine what all my engine stuff will bring...... What the hell do i do? As anyone knows the clutch doesn't just fall out of these cars lol so i really don't want to take all this crap back apart but i will if thats the answer but so far i haven't seen any reason why it vibrates.

 

It is not unusual for an imbalanced rotatating assembly to vibrate more at a particular RPM range than another. It's vibrating is because there is an imbalance, what the cause of the imbalance is, is anyone's guess.

If in fact the aftermarket flywheel is manufactured in such a way that the BALANCE weights from the old flywheel cannot be transferred into the appropiate locations in the new flywheel as stated in the service manual, that is a problem in my opinion.

I'm sure there will be a series of experts posting very soon telling us all how the service manual procedure is unecessary and how there car does not vibrate even though they did not follow it. I would not give much credence to an amateur that would dispute what an expert wrote.

I'm no expert on LS1s, I've just been fixing things long enough to know that the guy who wrote the book probably knew what he was talking about.